A mobile terminal device is configured with a display unit side housing and an operation unit side housing which are connected by a hinge portion, and has a structure in which a main display of the display unit side housing and operation keys of the operation unit side housing are exposed by pivoting thereof about the hinge portion to make an opened state.
Moreover, in such a mobile terminal device, a mode is provided in which the main display of the display unit side housing can be exposed, even in a closed state. In such a mode, the hinge portion is configured integrally with an opening-and-closing axis, which opens and closes the display unit side housing and the display unit side housing, and a pivot axis, which pivots the display unit side housing in a direction orthogonal to the opening-and-closing axis (e.g., Patent Documents 1 to 3).
[Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2003-336620
[Patent Document 2] Japanese Unexamined Patent Application, First Publication No. 2005-064931
[Patent Document 3] Japanese Unexamined Patent Application, First Publication No. 2005-286429